ACTG 274: When used as initial monotherapy, as well as following initial therapy with ZDV, ddI has been shown to be an effective anti-HIV agent. The addition of ribavirin, while possessing only limited anti-HIV activity on its own, potentiates the antiretroviral activity of DDI by enhancing the intracellular metabolism of ddI. While the active form of DDI is increased in the body through this mechanism, DDI related toxicities do not appear to increase, and the pharmacokinetic profile of ddI remains basically unchanged. The primary objectives of this two cohort protocol are to determine the safety, tolerance and pharmacokinetics of ddI when administered with ribavirin in HIV infected children ages three months to 12 years.